title: RET protein expression in papillary renal cell carcinoma.
abstract: OBJECTIVE
  To examine the role of RET in renal malignancy, in particular papillary renal cell carcinoma (RCC).
  
  
  METHODS
  A cohort of 111 archival renal samples was used consisting of 94 renal cancers (66 papillary RCC, 18 conventional clear cell carcinoma, 10 chromophobe RCC), 4 benign oncocytomas, and 13 normal kidney tissues. RET protein expression was examined by immunohistochemistry and expression levels were correlated with clinicopathologic and patient survival data.
  
  
  RESULTS
  Positive RET staining was seen in 34/66 (52%) papillary RCCs, 4/10 (40%) chromophobe carcinomas, 4/4 (100%) oncocytomas, and 11/13 (85%) normal kidney samples. All 18 cases of conventional clear cell carcinoma had negative RET staining. RET expression was associated with low Fuhrman nuclear grade.
  
  
  CONCLUSIONS
  RET protein may be contributing in part to an adaptation of a papillary growth pattern in certain renal malignancies. Given the possible therapeutic benefit of small molecule inhibitors of RET activation, further work needs to be done to highlight the functional relevance of RET protein expression in papillary RCC.
authors.affiliation: Department of Histopathology, St. James's Hospital, Dublin, Ireland.
authors.forename: Richard
authors.initials: R
authors.lastname: Flavin
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Finn
authors.forename: Toni K
authors.initials: TK
authors.lastname: Choueiri
authors.forename: Helen
authors.initials: H
authors.lastname: Ingoldsby
authors.forename: Martina
authors.initials: M
authors.lastname: Ring
authors.forename: Ciara
authors.initials: C
authors.lastname: Barrett
authors.forename: Miranda
authors.initials: M
authors.lastname: Rogers
authors.forename: Paul
authors.initials: P
authors.lastname: Smyth
authors.forename: Esther
authors.initials: E
authors.lastname: O'Regan
authors.forename: Eoin
authors.initials: E
authors.lastname: Gaffney
authors.forename: John J
authors.initials: JJ
authors.lastname: O'Leary
authors.forename: Massimo
authors.initials: M
authors.lastname: Loda
authors.forename: Sabina
authors.initials: S
authors.lastname: Signoretti
authors.forename: Orla
authors.initials: O
authors.lastname: Sheils
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D002292:Carcinoma, Renal Cell / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D051096:Proto-Oncogene Proteins c-ret / Q000032:analysis / Q000096:biosynthesis*
chemical_list: D014408:Biomarkers, Tumor; D051096:Proto-Oncogene Proteins c-ret; C099282:RET protein, human